In order to realize auto focusing of a camera module, a lens is required to be reciprocated in an object direction.
In general, the lens module includes a plate spring having a complicated shape at an upper and a lower part in order to support a lens holder including the lens.
FIG. 1 is a view showing a lens module of a general VCM (Voice Coil Motor) system.
The lens module 1 of FIG. 1 includes three lenses 2, 3 and 4, a lens holder 5 to adjust optical axes of the lenses 2 to 4 and to hold them, a yoke 6 arranged at an outer peripheral side of the lens holder, a magnet 6, a coil 7, and plate springs 8 and 9 to support the lens holder 5.
These parts are mounted on a base 10.
In this lens module 1, it is necessary that the respective parts of the plate springs 8 and 9 are processed to have high concentricity between the outer diameter and the inner diameter, and further, when assembled, it is necessary that the concentricity between the plate springs 8 and 9 is high.
Besides, when the lens holder 5 is not located at the center of the plate springs 8 and 9 with high accuracy, the center of gravity shifts to generate a tilt, and a partial blur occurs.